Sinaloan Mastiff Bats eat moths and some other insects, including beetles. They hunt most actively in the two hours after sunset and then again shortly before daybreak. When they roost, it is often in large groups, and often in houses or other buildings. Sometimes one male roosts alone, but groups of males have been found, as have groups of females - with an occasional male visitor. Males are a bit larger and heavier, and have throat glands that produce an oily substance that smells unpleasant to humans, but perhaps not to the bats. They seem to use it to mark females’ backs.

Females are ready to reproduce at a year of age, and usually have just one offspring a year, though very occasionally twins are born. The babies nurse for 6-8 weeks.

Length:
Range:
Head and Body: 69-85 mm; Tail: 41-52 mm

Weight:
Range:
14-28 g

References:

Allen, J.A, 1906. Bulletin of the American Museum of Natural History, 22:236.